Dental articulator.



PATENTED JUNE 30, 1908.

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JOHN G. FISHER, OF NEW YORK, N. Y.

DENTAL ARTICULATOR.

Specification of Letters Patent.

Patented June 30, 1908.

Application filed March 30, 1908. Serial No. 424,069.

T 0 all whom it may concern:

Be it known that I, JOHN C. Frsrrnn, a citizen of the United States, residing in the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Dental Articulators, of which the following is a specification.

My invention relates to the class of articulated plates used by dentists for the mounting of plaster casts or models, and is designed to afiord a simple, cheap and effective device in which the jaw plates may be opened into the same plane with relation to each other so as to ,rest evenly upon a flat surface and thereby afford a substantial base for the suport of the plaster molds when not required for actual use.

The invention consists in the construction and arrangement of parts hereinafter described and claimed specifically.

In the accompanying drawin s, Figure 1, is a plan of my improved denta-T articulator, opened with its jaw plates extending in the same plane; Fig. 2, is a side elevation of the same; Fig. 3, is a longitudinal section upon plane of ine 33Fig. 1; Fig. 4, is a side elevation of the articulator with the jaw plates shown parallel to each other; Fig. 5, is a central sectional view similar to Fig. 3, showing a slight modification in form; Fig. 6, is a lan of the central portion of the device sim' ar to Fig. 1, showing another modification.

The aw plates P, P, may be essentially the same in shape and structure, excepting that the knuckles 7c, 7c, of one plate fit snugly within those on the other plate, so that the parts are held against lateral movement with relation to each other when coupled together by the hinge pin h. One plate also carries the usual set screw S, by which the movement of the said plates towards each other is limited.

The outer flat portion of the jaw plates are formed with suitable slots or openings 0, 0, within, and between the edges of which, the bases of the plaster casts are embedded and held. The inner portions "L, i, of the jaw plates are inwardly and oppositely inclined with relation to each other,the inclination to the body of the plate being in each case approximately 45. Beyond these convergent inclined portions 2', i, are preferably the webs w, w, which support the knuckles 7c, 7c. The knuckles 7c, 76, extend beyond the inner edges (2, e, of the webs w, w, and the hinge pin holes p, p, may be formed in line with said inner edges 0, e, (as shown in Fig. 5), or slightly beyond said latter as shown in the other figures of the drawings. In fact if desired the webs may be nearly or practically dispensed with, as illustrated in Fig. 6,the essential feature of construction in this respect, being the projection of the knuckles beyond the inclined portions i, i, of the plates, with suflicient space between the opposed edges 0, c, of the plates to allow the main portions of the latter to be brought into the same plane, horizontal or otherwise. In other words when the flat main portions of the plates occupy a common plane, the axial plane of the hinge pin holes will be between the opposed inner edges 0, e, of the plates. As a result the maximum of stability is attained so that there is no danger of the device toppling or rolling over when thus extended, and the danger or injury to the casts is thereby greatly lessened.

l/Vhat I claim as my invention and desire to secure by Letters Patent is,

A dental articulator consisting of two jaw plates the main portions of which are flat with oppositely inclined convergent inner ortions formed withinterlocking knuc zles which project beyond said convergent portions and are formed with coinciding hinge pin holes occupying an axial plane between the opposed inner edges of the plates when the Hat portions of the latter are extended in a plane common to both, together with the hinge pin, for the purpose described.

JOHN C. FISHER.

l/Vitnesses:

GEO. WM. MIATT, D. W. GARDNER. 

